RRC ID 33595
Author Miwa Y, Nagura K, Eguchi S, Fukuda H, Deutscher J, Fujita Y.
Title Catabolite repression of the Bacillus subtilis gnt operon exerted by two catabolite-responsive elements.
Journal Mol. Microbiol.
Abstract Catabolite repression of Bacillus subtilis catabolic operons is supposed to occur via a negative regulatory mechanism involving the recognition of a cis-acting catabolite-responsive element (cre) by a complex of CcpA, which is a member of the GalR-Lacl family of bacterial regulatory proteins, and the seryl-phosphorylated form of HPr (P-ser-HPr), as verified by recent studies on catabolite repression of the gnt operon. Analysis of the gnt promoter region by deletions and point mutations revealed that in addition to the cre in the first gene (gntR) of the gnt operon (credown), this operon contains another cre located in the promoter region (creup). A translational gntR'-'lacZ fusion expressed under the control of various combinations of wild-type and mutant credown and creup was integrated into the chromosomal amyE locus, and then catabolite repression of beta-galactosidase synthesis in the resultant integrants was examined. The in vivo results implied that catabolite repression exerted by creup was probably independent of catabolite repression exerted by credown; both creup and credown catabolite repression involved CcpA. Catabolite repression exerted by creup was independent of P-ser-HPr, and catabolite repression exerted by credown was partially independent of P-ser-HPr. DNase I footprinting experiments indicated that a complex of CcpA and P-ser-HPr did not recognize creup, in contrast to its specific recognition of credown. However, CcpA complexed with glucose-6-phosphate specifically recognized creup as well as credown, but the physiological significance of this complexing is unknown.
Volume 23(6)
Pages 1203-13
Published 1997-3
PMID 9106211
MeSH Bacillus subtilis / genetics Bacillus subtilis / metabolism* Bacterial Proteins* Base Sequence Cyclic AMP Receptor Protein / genetics Cyclic AMP Receptor Protein / pharmacology* DNA Mutational Analysis DNA, Recombinant / genetics DNA, Recombinant / physiology DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism Enhancer Elements, Genetic* Gene Expression Regulation, Bacterial / genetics Gene Expression Regulation, Bacterial / physiology* Genes, Bacterial / genetics Genes, Bacterial / physiology* Glucose-6-Phosphate / genetics Glucose-6-Phosphate / metabolism Molecular Sequence Data Operon / genetics* Promoter Regions, Genetic / genetics Promoter Regions, Genetic / physiology Repressor Proteins / genetics Repressor Proteins / metabolism
IF 3.649
Times Cited 68
Prokaryotes B. subtilis MBS138 MBS139 MBS143 MBS144 MBS156 MBS157 MBS158 MBS159 MBS172 MBS173 MBS174 MBS175